All-Nanofiber Network Structure for Ultrasensitive Piezoresistive Pressure Sensors

Abstract

Sensing materials with fiber structures are excellent candidates for the fabrication of flexible pressure sensors due to their large specific surface area and abundant contact points. Here, an ultrathin, flexible piezoresistive pressure sensor that consists of a multilayer nanofiber network structure prepared via a simple electrospinning technique is reported. The ultrathin sensitive layer is composite nanofiber films composed of poly (3,4-ethylenedioxythiophene):poly (styrenesulfonate) and polyamide 6 (PEDOT:PSS/PA6) prepared by simultaneous electrospinning. PEDOT:PSS conductive fibers and PA6 elastic fibers are interwoven to form a multilayer network structure that can achieve ultrahigh sensitivity by forming a wealth of contact points during loading. In particular, gold-deposited PA6 fibers as upper and lower flexible electrodes can effectively increase the initial resistance. Due to this special fiber electrode structure, the sensor is able to generate a large electrical signal variability when subjected to a weak external force. The devices with different sensing properties can be obtained by controlling the electrospinning time. The sensor based on the PEDOT:PSS/PA6 nanofiber network has high sensitivity (6554.6 kPa −1 at 0−1.4 kPa), fast response time (53 ms), and wide detection range (0−60 kPa). Significantly, the device maintains ultrahigh sensitivity when cyclically loaded over 10,000 cycles at 5 kPa, which makes it have great prospects for applications in human health monitoring and motion monitoring.

Enhancing Strain-Sensing Properties of the Conductive Hydrogel by Introducing PVDF-TrFE

“…It can be concluded that the sensitivity of both the voltage and resistance responses of the Pp-250 improved after mixing the two fillers. Compared with other research results, ,,,,,− the Pp-250 prepared by us has more advantages in response time and recovery time indexes and can achieve a fast and sensitive response (Figure g).…”

Piezoelectric Nanoparticles for Ultrasound-Based Wireless Therapies

“…Moreover, the sol–gel process that typically involves the conversion of monomers into colloidal particle dispersion through hydrolysis and polymerization of precursors is used to prepare Na 0.5 K 0.5 NbO 3 nanosheet and ZnO nanosheet . In addition to thin film and colloidal nanoparticle, inverse opal scaffolds and electrospun nanofibers are also used as a piezoelectric nanoplatform for biomedical application …”

“…(a) Schematic representation of piezoelectric nanomaterial-based pressure sensor for health-monitoring applications. Adapted with permission from ref . Copyright 2022 American Chemical Society.…”

“…(vi) Monitoring wrist joint oscillation. Adapted with permission from ref . Copyright 2022 American Chemical Society.…”

“…High-frequency movements such as running can generate a large electrical output, whereas low-frequency movements such as walking give a low electrical output. In another work, a highly flexible piezoelectric organic polymer composed of poly­(3,4-ethylenedioxythiophene):polystyrene sulfonate and polyamide 6 is developed for health monitoring …”